Обсуждение: Help with a complex Update

I have a table of users and a table of user_actions.
I'd like to have a first_action column in the user table. 

How would I go about updating that info.

I'd immagine it'd be something like this:

update user_info set first_action = (select min(action_timestamp) from 
action_info where user_id = ?? current user id ??);

Is this possible or do I have to make an external for loop?
       Orion

On Fri, Nov 02, 2001 at 03:15:36PM -0800, Orion wrote:
> I have a table of users and a table of user_actions.
> I'd like to have a first_action column in the user table. 
> 
> How would I go about updating that info.
> 
> I'd immagine it'd be something like this:
> 
> update user_info set first_action = (select min(action_timestamp) from 
> action_info where user_id = ?? current user id ??);

Guessing at your table schema, but I think you want:
update user_info set first_action =  min(action_timestamp) from action_info where action_info.user_id = user_id;

Ross

Orion,

> update user_info set first_action = (select min(action_timestamp)
> from 
> action_info where user_id = ?? current user id ??);

Close.  You need to use a subselect in the FROM clause:

UPDATE user_info SET first_action = min_action
FROM (select user_id, min(action_timestamp) as min_action      FROM action_info WHERE user_id = $user_variable
GROUPBY user_id) ma
 
WHERE user_info.user_id = ma.user_id;

-Josh 

______AGLIO DATABASE SOLUTIONS___________________________                                      Josh Berkus Complete
informationtechnology      josh@agliodbs.com  and data management solutions       (415) 565-7293 for law firms, small
businesses       fax 621-2533   and non-profit organizations.      San Francisco